Method of treating undried organic nitrates and the like



Un tas stares ATENT @FFEQE.

WALTER 0. SN ELLING, OF ALLEN TO? N, PENNSYLVANIA, ASSIGNOR TO TROJANPOWDER COZMPANY, 03? N EW YORK,

N. Y., A CORPORATION OF NEW YORK.

METHOD OF TREATING UN DRIED ORGANIC NITRATES AND THE LIKE.

Specification of Letters Patent.

Patented Nev. 1, 1921.

'No Drawing. Original application filed March 16,1920, Serial No.366,390. Renewed January 21, 1921,

Serial No. 439,054. Divided and this applica To all whom it may concern:

Be it known that I, IVALTER O. SNELLING, a citizen of the United'States,and resident of Allentown, Lehigh county, Pennsylvania, have inventedcertain Improvements in Methods of Treating 'Undried Organic Nitratesand the like, of which the following is a specification. I

My invention relates to the manufacture of explosives and similarmaterials which, owing to the manufacturing processes employed, areobtained in wet condition, and the object of the invention is'to providea method for reducing the water content of such materials withoutdrying. While my invention may be utilized in the manufacture of anumber of materials, I have found it particularly useful as applied tothe manufaoture of explosives, and for purposes of specific illustrationwill describe it in connection with such manufacture.

In the manufacture of nitrocellulose, nitrostarch and other solidorganic nitrates, said materials, following the nitration and washingprocesses, are in wet condition, and it has hitherto been the practiceto dry them before mixing with other ingredients to produce commercal ormilitary explosives. Even where it has been desired to produce a wetfinished explosive, the preliminary drying process has been deemednecessary because of the undue amount of water present with the organicnitrate following thewashing process. WVhile it is manifestly desirableto avoid the drying operation by utilizing the nitrostarch ornitrocellulose in wet condition, as in this way an important item ofexpense and danger is avoided, experiments have shown that explosives ofproper sensitiveness cannot be made by the mere mixing of salts withundried nitrostarch or nitrocellulose. For example, nitrostarch aftercoming from the centrifuge and having its water content reduced thereinto the lowest obtainable amount, still contains an average of about 20%of moisture. If now such wet nitrostarch is mixed in equal parts withnitrate of soda or with nitrate of ammonia the completed mix will stillcontain 10% of moisture, and this is higher than the amount which such amix can contain and still detonate with certainty with such detonatingcaps as are commercially used. It is true that by using a smaller amountof the wet tion filed March 16, 1921. Serial No. 452,733.

nitrostarch, and a greater amount of the nitrate, mixtures having alower water content can be obtained. One part of wet nitrostarch may forexample be mixed with three parts of sodium nitrate, and in this case ifthe initial nitrostarch contained 20% of water the final mix willcontain but 5% of water. Such a mix is, however, quite as insensitive asthe, mixture previously described, and which contained 10% of water, forthe reason that the amount of nitrostarch has been reduced in proportionas the water has been reduced, the first mixture containing 40% ofnitrostarch on a dry basis, and 10% of water, and the second mixturecontaining 20% of nitrostarch on a dry basis, and 5% of water, and bothof these mixtures being relatively insensitive to detonation.

Repeated experiments have shown that there are no proportions in whichwet nitrostarch or wet nitrocellulose, after drying to the maximumextent possible in a centrifugal wringer, can be mixed with nitrate ofsoda or with nitrate of ammonia to form an explosive susceptible todetonation with certainty by the detonators com and then applycentrifugal force to remove the excess, thereby substituting a solutionof ammonium nitrate for the water which is normally present in the wetmaterial.

As the result of this first stage of my procedure, I obtain instead ofnitrostarch wet with 25% of water, nitrostarch which contains 25% of aconcentrated solution of ammonium nitrate. As the water originallypresent in the nitrostarch tends to dilute my original ammonium nitratesolution, in ordinary procedure I obtain an absorbed solution containingabout 50% by weight of ammonium nitrate, and my nitrostarch containsabout 25% by weight of this solution, after moderate wringing.

If I now mix equal Weights of the nitrostarch so prepared with ammoniumnitrate, I obtain a mixture which contains 37.5% of nitrostarch, 56.25%of ammonium nitrate, and 6.25% of water. This mixture is sensitive tocommercial detonators, and forms a highly desirable explosive. I mayemploy of my wet nitrostarch and 80% of ammonium nitrate, and in thiscase my finished explosive contains 52.5% of nitrostarch, 38.7 5% ofammonium nitrate, and 8.75% of water, this explosive also beingsensitive to a commercial detonating cap.

From the foregoing illustration it will be seen that while the liquidcontent of the explosive material is not reduced, the water content hasbeen reduced, a portion of the latter being replaced by an ingredienthaving a function in the finished explosive. Obviously other inorganicoxidizing salts having a high solubility in water may be substituted forammonium nitrate, such, for example, ascalcium nitrate, or ammonium orsodium or potassium chlorate or perchlorate. In the manufacture of someexplosives, or other material, the diluting solution need notnecessarily be that of a salt performing any function in the finishedproduct other than the diluting function,

the method in its broader aspect contemplating the reduction of thewater or other liquid content of a wet material by replacement by aconcentrated solution of an inorganic salt.

As the solubility of most salts in water is increased by temperature, Iobtain a greater drying effect when I use a warm concentrated solutionthan when I use a cold concentrated solution, since in the former casethere is a greater proportion of the solid material in the liquidremaining in the treated material at the close of the process. ithmaterials such as potassium chlorate and potassium perchlorate the useof hot solutions is quite desirable, since these materials are much moresoluble in warm water than in cold.

The solid salt which is admixed with the wet organic nitrate prepared asdescribed in this application may or may not be the same material ofwhich a solution is used for diluting the water originally present inthe organic nitrate. For example, the water originally present inundried nitrated starch may be replaced by a concentrated solution ofammonium nitrate and the wet nitrostarch so prepared may then be mixedwith dry ammonium nitrate or the nitrated starch prepared as describedmay be mixed with dry sodium nitrate, or with dry ammonium perchlorateor with any other suitable dry salt or mixture of dry salts. In-

stead of a solution of ammonium nitrate or other inorganic salt I mayuse a concentrated solution of any solid body having high solubility inwater.

I do not in this application claim the method which involvessubstituting for the water in a mixture of a wet inorganic nitrate asolution of a solid body by a displacement process, as said method formsthe subject of my application Ser. No. 439,054, of which this is adivision.

I claim: p

1. The method of treating wet materials to reduce the water contentwithout drying which comprises the step of mixingthe'material with aconcentrated solution of a solid body having high solubility in water,and subsequently removing the excess solution.

2. The method of treating wet materials to reduce the water contentwithout drying which comprises the step of thoroughlymixing said wetmaterial with a solution of an inorganic salt and removing by suitablemeans the excess solution.

3. The method of treating wet materials to reduce the water contentwithout drying which comprises the step of thoroughly mixing said wetmaterial with a solution of an inorganic salt and removing by suitablemeans excess water substantially correspending in amount to theinorganic salt added.

4. Inthe method of manufacturing explosives and the like containing asolid organic nitrate, the step which comprises mixing the undriedorganic nitrate with a concentrated solution of an inorganic salt, andsubsequently removing the excess solution.

'5. The method of manufacturingwet ex-.

plosives containing an organic nitrate and an inorganic salt whichcomprises mixinga wet organic nitrate with a solution of an inorganicsalt, and subsequently removing the excess solution. V 6. The process ofmaking a wet explosive containing a solid organic nitrate and aninorganic salt without drying said organic nitrate, which comprisesreducing the amount of water content in said organic nitrate to arequired amount by mixing therewith a solution of said inorganic salt,removing excess solution and thereafter adding sufiicient of the dryinorganic salt to secure the desired proportion of the severalingredients.

7 The method of manufacturing a wet nitrostarch-ammonium nitrateexplosive, which comprises mixing undried nitrostarch with aconcentrated solution of ammonium nitrate, removing by centrifugalaction sufficient liquid to leave in the mass a desired proportion ofwater, and adding dry ammonium nitrate.

WALTER O. SNELLING.

